The present invention relates to data storage devices, and more particularly, to techniques for storing system images in slices on data storage devices.
Currently, a significant amount of time is required to perform a complete backup of a full hard disk drive. The increasing data storage capacity of hard disk drives slows down the backup process. For example, backing up a 160 gigabyte (GB) hard disk drive at 50 MB/second that is only 50% full takes about 30 minutes.
Restoring a previous system image on a hard disk drive takes even more time than performing a backup. If the image was in a compressed format, the image has to be copied back to the hard disk drive. Often, the hard disk drive has to be physically swapped with the restored version. In some cases, the restoration effort may be required to recover only a single file.
A computer system is typically blocked when a full hard disk drive image backup is occurring. Otherwise, an inconsistent state may be saved in the backup image. Non-blocking backups operate at the file level in order to lock every single file for backup, but they may not be enough to guarantee system consistency.
Other issues with backups relate to storing multiple versions and security. The management of multiple backup copies can be cumbersome and error prone. Also, each backup copy should have the same security-level of the original image in terms of access, control, confidentiality, and integrity.